A national screening programme for prostate cancer could eventually save one in five sufferers – but would also lead to over-diagnosis and a huge rise in dangerous side-effects to treatment, a major study has concluded.
The question of whether men should be screened for prostate cancer – in the same way women over 50 are screened for breast cancer – has been a source of contention for many years.
A blood test exists, but it is of low accuracy and over-diagnoses symptoms which turn out to be harmless in around 40 per cent of cases. More invasive tests, including biopsies, are required after a positive result, which carry a high risk of side effects. Over-treatment of an otherwise benign condition can lead to other serious problems including incontinence and impotence.
The new study analysed the long-term outcomes of more than 162,000 men from eight European countries, some of whom received the prostate-specific antigen test every four years.
In the group who had been screened, prostate cancer deaths were reduced by 15 per cent after nine years, and 22 per cent after 11 years. However, 781 men needed to be tested to prevent one prostate cancer death – a figure the study’s authors said would lead to an intolerably high level of harm from over-treatment, with potentially thousands of men suffering side effects.
Study leader Professor Fritz Schröder of the Erasmus Medical Center in Holland, said that the reduction in deaths as a result of screening was similar or greater to that achieved by breast cancer screening, but concluded that “the time for population-based screening has not arrived”.
“Further research is urgently needed on ways to reduce over-diagnosis, preferably by avoiding unnecessary biopsy procedures, and reducing the very large number of men who must be screened, biopsied and treated to help only a few patients,” he said.
The findings, published in The Lancet medical journal today were backed by the charity Prostate Cancer UK, which also called for urgent research into a test which could “distinguish between dangerous cancers that could go on to kill, and those which may never cause harm.”
Prostate cancer kills around 11,000 men in the UK every year – accounting for seven per cent of all cancer deaths.